04/20/2007 at 02:00 PM EDT
Alec Baldwin apologized Friday for his angry voicemail to his daughter
, blaming the stress of his custody fight with Kim Basinger and insisting: "I have a normal relationship with my daughter."
"I'm sorry, as everyone who knows me is aware, for losing my temper with my child," the actor wrote on his Web site
. "I have been driven to the edge by parental alienation for many years now. You have to go through this to understand. (Although I hope you never do.) I am sorry for what happened."
He added: "I have endured a great deal over the last several years in my custody litigation. Everyone who knows me privately knows that certain people will go to any lengths to embarrass me and to disrupt my relationship with my daughter."
Baldwin posted his comments on his site's guest book under the heading "Alec responds to your comments" a day after the leak to TMZ.com
of a voicemail message from Baldwin to his and Basinger's 11-year-old daughter, Ireland.
The message had been contained in a sealed court file in the former couple's three-year custody fight over the girl, who lives with her mother in Los Angeles.
Baldwin's attorneys on Friday filed papers asking the court to investigate the source of the leak, saying Basinger was "the only parent with custody, possession and control of the minor child's telephone voicemail message."
"This is a direct violation of a court's order to keep items sealed," Baldwin's attorney Vicki Greene tells PEOPLE. "It's ultimately damaging the minor child, and the tape had to have come from Basinger's side. Neither we or the court had a copy, so where else could it have come from?"
Basinger's attorney didn't respond to requests for comment. Her Hollywood rep says only, "The voicemail speaks for itself."
"I am sorry for what happened," Baldwin wrote on his Web site. "But I am equally sorry that a court order was violated, which had deliberately been put under seal in this case. Although I have been told by numerous people not to worry too much, as all parents lose their patience with their kids, I am most saddened that this was released to the media because of what it does to a child," he wrote.
He said that in high-profile cases, "your opponents attempt to take a picture of you on your worst day and insist that this is who you are as a person. Outside the doors of divorce court, I have friends, I have respect from people I work with and I have a normal relationship with my daughter. All of that is threatened whenever one enters a courtroom."
He said he would be writing about the "incredible strains created by parental alienation" in a book, but "in the meantime, I'm sorry to anyone who's taken offense from this episode."
(Parental alienation, a hotly debated topic in custody cases, is a situation in which one parent is said to alienate the child from the other.)